Safety paper and process for making it



Patented Mar. 3, 1936 UNlTED STATES ssrn'rr PAPER! AND rnocsss ron MAKING IT Frank S. Wood, Newton, Mass assignmto Frank W. Wood, Astoria, N. Y.

No Drawing. Application August 18, 1933,

Serial No. 685,492

3 Claims.

This invention relates to improvements in that class of so called safety papers that have a color design marked or printed upon one or both surfaces, in fugitive inks of various tints, whereby they become safety papers as the result of this separate operation, and has for its objects an increased protection in novel color effects, at less cost, by doing away with the necessity for coloring by a separate operation.

Heretofore, the color effects of safety paper in the various designs known to the art, have been produced by putting rolls of paper thru a mechanical surface marking and. refinishing after the paper had been shipped from the paper-mill to the coloring plant. This increases the cost of the paper from 50% to 100% according to the coloring method used.

Instead of depending upon this agency for providing safety colors, I employ fugitively dyed colored fibers in the heaters and thus do awaywith the expense of this rehandling. The all-' over colors heretofore used for safety 'paper,.

make it impracticable to do artistic and attractive lithographing in delicate tints upon the dead safety paper colors; while the color effects produced by my invention lend themselves to all degrees of attractive lithography as well as an increased protection against alteration by the criminal artist.

I am aware that paper of a similar appearance to the eye hasbeen previously made both as a cover paper and as anovelty note paper but neither of these papers were adapted for safety paper nor had any of its essential characteristics. What I claim as my invention is such chemical and mechanical improvements as result in turn-. ing out a safety paper in novelty colors and sensitivity and the process by which it is produced by one continuous operation as will be hereinafter described. It is different from all other papers because the color and sensitivity effects are produced in the early stages of the paper-making process and before the paper is formed into its web on the screen. I am aware that others have produced many complexities involving surface and color-marking after the paper has been. finished, by means of subsequent mechanical processing and operations but so far as I know I am the first to produce the paper herein described by applying a safety feature to the pulp before it is formed into a web of paper, and to apply color to that pulp in such a way as to do away with mechanical processing, printing and surface-marking which all safety papers now require under the present state the art. I am of the paper after it has been formed into a web 5 or sheet.

limit to use fibers of the same materiaLas the pulp but fugitively dyed with a different color from the rest of the pulp but I have overcome this difliculty and produced a commercial paper in a new way and for new and useful purposes which do away with one or more operations in the making of safety paper. I also claim that this invention is an improvement, in color efiects, upon my ink set invention alreadypatented No. 1,900,067.

To that end, I have discovered that by using diminutive fibers colored with fugitive dyes and mixing these colored fibers with a white, writingpaper furnish, it is practicable to turn out a finished safety paper at the end of a paper-machine; that this finished safety paper has a color effect due to the fibers but remains a white paper with colored irregular lines therein so minute as to require several to equal the breadth of a hair; that such safety paper when once written on with ink prevents the removal of the writing by ink eradicators or abrasives without also removing the colored lines; and that it is to the greatest degree difficult either to replace the microscopical lines or to match the colors thereof or to photograph them.

It is a well-known fact that delicate tints of all colors cannot be reproduced by photography. It'is obvious that microscopical fibers, in delicate tints, cannot be photographed by any known method. When it is considered that my invention comprehends not only delicate tints of microscopical minuteness but also a surface appearance that never repeats itself in 'any two square Heretofore, it has been extremely difinches on the web of paper, the impracticability of reproduction by photography or lithography is self evident.

I have also discovered that the use of alkaline colors in the fibers adapts the paper for treatment by my ink set solutions without interfering with the delicate color effect; whereas the useof acid colors for this purpose is prohibitive forthe reason that the ink set solutions break down and destroy the acid colors. p

In making this paper any fibrous material may be used but I prefer to use the same pulp out of which the paper is made as it makes a perfect homogeneous mixture, ,a smooth writing surface, and can be beaten so fine that a hair looks coarse very delicate pink; a golden-rod fiber gives the paper the appearance of being a light buff; and so on. Enough of these colored fibers are added to a beater of white, writing-paper furnish to give the paper a similar appearance to that which silk threads give to portions of banknotes or United States currency. This may be varied according to the tint to be desired; the deeper the tint, the more fibers have to be used, and vice versa. I prefer to use less than a pailful of colored fibers to a beater of furnish; but any skilled papermaker may readily determine upon any standard of fibers for a certain depth of color. The use of silk threads in government paper has a special object that need not be described since it has nothing to do with the color of the paper; while in my invention the primary purpose of the fibers is to give apparent color toa paper which still retains its basic white. Therefore it requires many more of the colored fibers for my purpose. In the government paper the silk threads are dyed a fast color; while in my invention the fibers are-dyed in fugitive water-soluble aniline colors that bleach under the action of chlorine and are removable under the use of abrasives.

Paper thus prepared is reeled up at the end of a paper-machine as a completedsafety paper by one continuous operation, in whatever color effect is being run, and is ready for check imprinting or lithography. Instead of having a design printed or marked upon its surfaces, it has the natural design that the fibers take from the mechanical motions of the machine in placing them during the paper-making process.

In this type of safety paper, tampering with it is supposed to remove the fugitive tint or color when the ink is eradicated. The criminal artist then raises the check, matches up the color and re-tints it by hand, in whatever design the paper is made. With my invention, this is most diiilcult for two important reasons. First, the color comes out of the fibers leaving a white, blank space on the check without any design to match up; second, the fibers are so fine that no pen can reproduce the lines and any attempt to do so is made obvious to the trained eye of a bank-teller by one or more tell-tale danger signals. Moreover, on account of the fineness of the colored fibers, it is a. physical impossibility to match the color even if it were possible to restore the paper-machine made design so that nobody would notice it.

This new banknote safety paper may be made as above described by using either acid or alkaline colors on the fibers.

The banknote safety paper is adapted to ink set treatment by coloring the fibers with alkaline colors and then proceeding according to specifications in my application for a. patent for an ink setting process, Serial No. 552,550 filed July 22, 1931, issued as U.' S. Patent No. 1,964,791 dated July 3, 1934, which see for details.

Another variation of this paper adapts it for a protective, safety wrapping paper. It is common report that packages are being imitated, counterfeited and their contents substituted, in many,

well known, established products. One of the objects of my invention is to make it difiicult to imitate a protective wrapper, and easy to detect the imitation.

This is accomplished by taking my banknote or fiber paper, of any tint, and coating it. The coattearing and proclaims its honesty while the lack of fiber in the imitation gives conclusive evidence of its fraudulent character. a

It is my purpose to sell no. paper except direct to concerns of repute in which event it will be impossible to counterfeit the wrapper except by unlawful conspiracy and collusion with some paper-mill. This is believed to be a very remote possibility.

It is obvious that each large consumer of this paper may have a special, exclusive, identifying fiber color.

What I claim is:

1. A banknote safety paper comprising a variably tinted base or body color and a relatively small quantity of colored fibers of the same material, dyed in water-soluble, fugitive dye and of a nature to be attractively distributed throughout the base in the form of an unrepeating infinity of irregular colored lines adapted to disappear upon eradication, said safety paper having a nature that excludes the necessity for all other dyeing and surface marking steps and requires no processing or surface-marking subsequent to its formation in the web.

2. The process of manufacturing a banknote safety paper comprising: (1) Dyeing a relatively small quantity of pulp with a water-soluble, fugitive dye adapted to create a delicately tintedpaper by means of an infinity of irregular, colored lines into which said colored pulp is transformed by mixing; (2) preparinga relatively large quantity of uncolored, identical pulp adapted to be created into a delicately tinted paper by mixing with colored pulp; (3) the mixing of said colored and uncolored pulps at a stage in the paper making previous to the web formation, whereby said mixing creates a delicately tinted paper of infinite variation in design of a nature that obviates the necessity of processing or surface-marking subsequent to the web formation and excludes the necessity for all other dyeing or surface marking steps.

3. A banknote safety paper comprising a variably tinted base or body color and a relatively small quantity of colored fibers of the same material, dyedin water-soluble, fugitive dye and of a nature to be attractively distributed throughout the base in the form of an unrepeating infinity of irregular colored lines adapted to disappear under photography, said lines producing a condition that excludes the possibility of focusing a camera so as to reproduce either a limited area of said safety paper or'its unrepeating infinity of variations.

W S. WOOD. 

